1. Field of the Invention
This invention relates to a balancer control device for a four-cycle multiple-cylinder engine, and more particularly to a balancer control device for a four-cycle multiple-cylinder engine which can be operated in a state in which only two of the cylinders are operative.
2. Description of the Prior Art
There has been known a multiple-displacement engine which can be operated either in a full-displacement mode or in a partial-displacement mode according to the operating condition of the engine. Generally, in engines of this kind, fuel supply to a part of the cylinders is cut to make these cylinders inoperative (the partial-displacement mode) when the engine is operated under light load. (See, Japanese Unexamined Patent Publication No. 57(1982)-338, for example.)
In a multiple-displacement engine in which two cylinders are operated in the partial-displacement mode so that the power stroke of one cylinder occurs with a crank angle phase difference of 360.degree. with respect to the power stroke of the other cylinder, a large primary vibration generating moment is generated in the engine structure due to torque fluctuation caused by explosion in the operative cylinders, thereby lowering the driving comfort.
The present state of the art is disclosed in Japanese Unexamined Patent Publication No. 57(1982)-338, Japanese Patent Publication No. 58(1983)-4221, U.S. Pat. No. 4,337,740, U.S. patent application Ser. No. 643,146 now U.S. Pat. No. 4,556,026 and Japanese Unexamined Utility Model Publication No. 58(1983)-49047.